Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 188,886	$ 159,207	$ 178,040
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	144,572	156,501	147,129
Asset impairments	4,706	1,580	614
Amortization of debt issuance costs and other non-cash interest	3,351	3,419	3,222
Expenses associated with debt refinancing transactions	602	1,016
Deferred income taxes	(1,162)	(4,436)	921
Other expenses and non-cash items	13,033	7,909	4,267
Non-cash revenue and other income	(11,292)	(14,509)	(14,528)
Non-cash equity compensation	17,267	13,132	13,286
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets	(16,938)	(19,470)	(13,913)
Accounts payable, accrued expenses and other liabilities	11,359	18,531	22,287
Net cash provided by operating activities	354,384	322,880	341,325
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions	(136,128)	(58,239)	(17,576)
Expenditures for other capital improvements	(57,192)	(63,438)	(56,168)
Acquisitions, net of cash acquired	(48,396)	(175,588)	(48,867)
Proceeds from sale of assets	4,295	12,911	970
Increase in other assets	(7,168)	(6,703)	(3,605)
Payments received on direct financing lease and notes receivable			684
Net cash used in investing activities	(244,589)	(291,057)	(124,562)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt and borrowings from credit facility	1,146,691	809,831	475,500
Scheduled principal repayments	(14,121)	(7,816)	(10,000)
Principal repayments of credit facility	(648,000)	(603,500)	(461,500)
Satisfaction and discharge of senior notes	(325,000)
Payment of debt issuance and other refinancing and related costs	(4,296)	(6,087)	(4,169)
Payment of lease obligations for financing leases	(538)	(3,744)	(2,483)
Contingent consideration for acquisition of businesses	(7,398)	(1,500)
Proceeds from exercise of stock options	876	2,367	6,534
Proceeds from sale/leaseback		7,783
Purchase and retirement of common stock	(3,531)	(3,005)	(5,847)
Dividends paid	(209,522)	(204,198)	(200,326)
Net cash used in financing activities	(64,839)	(9,869)	(202,291)
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	44,956	21,954	14,472
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of period	74,137	52,183	37,711
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of period	119,093	74,137	52,183
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Debt assumed on acquisition of property		157,280
Establishment of right of use assets and lease liabilities	137,946
Cash paid during the period for:
Interest (net of amounts capitalized of $6.0 million, $1.0 million, and $0 in 2019, 2018, and 2017, respectively)	85,698	71,787	57,485
Income taxes paid	$ 16,437	$ 13,303	$ 8,089